Re: [Qemu-devel] [PATCH v2] raw-posix.c: Make physical devices usable in QEMU under Mac OS X host

[Stefan Hajnoczi <stefanha@gmail.com>]

On Mon, Jul 20, 2015 at 5:17 PM, Programmingkid
<programmingkidx@gmail.com> wrote:
>
> On Jul 20, 2015, at 8:46 AM, Laurent Vivier wrote:
>
>> -----BEGIN PGP SIGNED MESSAGE-----
>> Hash: SHA1
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>>
>>
>> On 20/07/2015 12:48, Stefan Hajnoczi wrote:
>>> On Fri, Jul 17, 2015 at 03:24:34PM -0400, Programmingkid wrote:
>>>>
>>>> On Jul 17, 2015, at 9:41 AM, Stefan Hajnoczi wrote:
>>>>
>>>>> On Thu, Jul 16, 2015 at 04:46:07PM -0400, Programmingkid
>>>>> wrote:
>>>>>> @@ -2014,7 +2015,9 @@ kern_return_t GetBSDPath( io_iterator_t
>>>>>> mediaIterator, char *bsdPath, CFIndex ma if (
>>>>>> bsdPathAsCFString ) { size_t devPathLength; strcpy( bsdPath,
>>>>>> _PATH_DEV ); -            strcat( bsdPath, "r" ); +
>>>>>> if (flags & BDRV_O_NOCACHE) { +
>>>>>> strcat(bsdPath, "r"); +            } devPathLength = strlen(
>>>>>> bsdPath ); if ( CFStringGetCString( bsdPathAsCFString,
>>>>>> bsdPath + devPathLength, maxPathSize - devPathLength,
>>>>>> kCFStringEncodingASCII ) ) { kernResult = KERN_SUCCESS;
>>>>>
>>>>> Is this the fix that makes CD-ROM passthrough work for you?
>>>>>
>>>>> Does the guest boot successfully when you do:
>>>>>
>>>>> -drive if=ide,media=cdrom,cache=none,file=/dev/cdrom
>>>>
>>>> The guest fails during the boot process with the above command
>>>> line.
>>>
>>> That means the issue you originally hit hasn't been solved yet.
>>>
>>> Take a look at s->needs_alignment and raw_probe_alignment().  In
>>> the -drive cache=none case raw-posix needs to detect the correct
>>> alignment (probably 2 KB for CD-ROMs).
>>
>> As raw_open_common() sets needs_alignment to true on BDRV_O_NOCACHE
>> (cache="none") and raw_probe_alignment() detects alignment if
>> needs_alignment is true, I don't understand why it doesn't work.
>>
>> Could you explain ?
>
>
> I just did several tests with real CD-ROM discs and it does work. I first booted up Mac OS 10.2 with Stefan's command options using a professionally made CD, and it worked. I then did the same test again using a burned CD-R disc and it also worked. The last test I did was just listing the files from OpenBIOS using this: qemu-system-ppc -drive if=ide,media=cdrom,cache=none,file=/dev/cdrom. All tests were a success.
>
> Mac OS 10.2 panicked while booting in the original test using Stefan's command. I remember the panic happened about a minute into the boot process, so it could have been a guest issue rather than a QEMU issue. Either way everything is working now.

I don't see what your patch changed to make -drive
if=ide,media=cdrom,cache=none,file=/dev/cdrom work?

Stefan